Product spreading machine and method

ABSTRACT

A machine for automatically spreading an even layer of shredded or particulate products on relatively large flat items includes a surface comprising either a shaker tray or, preferably for sticky products, a stationary louvered air pan positioned over a conveyor line extending through an open-ended rotating drum. Elongated rake-like members circumferentially spaced around the inside of the drum carry portions of the products from the bottom of the drum to a discharge point above the shaker tray or air pan. Oscillations of the tray or a cushion of air fed from a plenum below the louvered pan cause the products to move laterally and to cascade evenly over a lip that extends diagonally across the conveyor line to cover items transported along the line. Features of the apparatus include a torsional stabilizer to prevent racking of the shaker tray by unequal actuator forces, a specially shaped plenum to produce uniform air velocity across the louvered pan, adjustable rake members that are easily removed for cleaning, air blast discharge of products from the rakes onto the tray, and a conveyor transfer station at the exit end of the drum to prevent excess product carryout.

United States Patent [191 Eisenberg [451 Sept. 16, 1975 PRODUCT SPREADING MACHINE AND METHOD [75] Inventor: Bernard Eisenberg, Rockaway, NJ.

[73] Assignee: Solbern Corporation, Fairfield, NJ.

[22] Filed: Dec. 4, 1973 [21] Appl. No.: 421,692

[52] US. Cl. 118/24; 118/308; 141/78; 141/131 [51] Int. Cl. BOSC 5/00; BOSB 3/00 [58] Field of Search ll8/DIG. 4, 13, 17, 19, 118/24, 324, 326, 308; 426/289; 141/78, 131

[56] References Cited UNITED STATES PATENTS 2,937,670 5/1960 Eisenberg 141/131 3,045,640 7/1962 Hill et a1. 118/21 3,217,760 ll/1965 Eisenberg 141/78 3,283,740 1 H1966 Fredricksen .1 118/24 3,298,404 1/1967 Eisenberg 141/131 3,376,849 4/1968 Squier 118/308 3,759,218 9/1973 Korstvedt 118/22 Primary Examiner-Mervin Stein Assistant Examiner-Douglas Salser Attorney, Agent, or FirmKenyon & Kenyon Reilly Carr & Chapin 57 ABSTRACT A machine for automatically spreading an even layer of shredded or particulate products on relatively large flat items includes a surface comprising either a shaker tray or, preferably for sticky products, a stationary louvered air pan positioned over a conveyor line extending through an open-ended rotating drum. Elongated rake-like members circumferentially spaced around the inside of the drum carry portions of the products from the bottom of the drum to a discharge point above the shaker tray or air pan. Oscillations of the tray or a cushion of air fed from a plenum below the louvered pan cause the products to move laterally and to cascade evenly over a lip that extends diagonally across the conveyor line to cover items transported along the line. Features of the apparatus include a torsional stabilizer to prevent racking of the shaker tray by unequal actuator forces, a specially shaped plenum to produce uniform air velocity across the louvered pan, adjustable rake members that are easily removed for cleaning, air blast discharge of products from the rakes onto the tray, and a conveyor transfer station at the exit end of the drum to prevent excess product carryout.

17 Claims, 9 Drawing Figures ATENTEU SEP 1 6 513 SHEET 2 HF PATENIEB SE? 1 5 i875 ssazn 3 UP 4 PRODUCT SPREADING MACHINE AND METHOD BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to machines and methods for evenly distributing shredded or particulate products on the top of individual items and particularly to machines and methods for spreading or shaking topping products on food items.

2. Description of the Prior Art.

My previous U.S. Pat. No. 2,937,670, issued May 24, 1960; No. 3,217,760, issued Nov. 16, 1965; No. 3,298,404, issued Jan. 17, 1967; and No. 3,696,581 issued Oct. 10, 1972 disclose rotary-drum machines of the same general type as the spreading machine of the present invention, and their disclosures are incorporated herein by reference.

In these prior machines, buckets, shelves or fixed rake members spaced circumferentially around the inside of a horizontal or slightly inclined rotating drum pick up portions of food materials in the bottom of the drum as it rotates and carry the portions to the top of the drum where the materials are released onto a distribution plate or a shaker tray for delivery into a line of receptacles extending through the drum.

The release point for the materials from the rakes in these prior machines is determined either solely by gravity acting to slide the material off the rake tines as their slope continually increases with rotation of the drum (see FIG. 7 of U.S. Pat. No. 3,217,760) or by opening pincer-like secondary rakes (see FIG. 14 of U.S. Pat. No. 3,696,581 The first arrangement has the advantage of simplicity, but release occurs over a relatively wide angle of drum travel. The release point of the second arrangement is precise, but the dual rake system is complicated and adds to difficulty of cleaning the apparatus. Undesired buildup of stringy food product on the rakes of the latter arrangement is avoided, however, by using air nozzles connected to a common supply pipe mounted outside the drum at the release point, the nozzles directing streams of air through the screen covering the drum to dislodge any food particles stuck to the tines of the opened pincer rakes.

In the prior machines the discharge edge of the shaker tray typically extends directly above and parallel to the centerline of the conveyor; so that each receptacle is progressively filled by material cascading over the edge, as the receptacle moves along the line. Settling and distribution of the materials inside the receptacles is accomplished by shaking the receptacles, and any overfill drops down to the bottom of the drum for recycling. This tray configuration was found not to be satisfactory. however, for spreading shredded or particulate materials evenly over flat food items as, for example, spreading cheese, peppers, sausage, anchovies and the like uniformly over pizza pies. In that situation the materials shaken from the tray would form a single ridge along the centerline of a pizza pie without spreading uniformly across the entire upper surface of the pie.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved rotary-drum product handling apparatus and method for uniformly distributing shredded or particulate products over individual items moving along a con veyor line by moving the products laterally across a flat surface positioned over the conveyor line so that the products cascade evenly over an edge of the surface that extends diagonally across the line of items.

Another object of the invention is to provide a drumtype product spreader having single fixed-angle rake members for product pickup yet with a precisely controlled rake discharge point above a shaker pan.

Another object of the invention is to provide a product spreader of the type described having adjustable length rake members for varying the amount of product picked up, the rake also being easily removable for cleaning.

It is another object of the invention to provide a torsional stabilizer mounting for a pneumatically actuated shaker tray to prevent the tray from racking as a result of unequal operation of the pneumatic actuators.

Another object of the invention is to provide a uniform velocity air cushion above the surface of a flat pan for moving products across the surface without sticking or clogging.

Still another object of the invention is to provide a rotary-drum type product spreader in which all excess product falling on the conveyor is retained inside the drum, and only product that is deposited on items to be covered is carried out of the machine.

Yet another object of the invention is to provide means for automatically removing excess product adhering to the conveyor surface once for each full circuit of the conveyor element to prevent long term product buildup with potential resulting contamination in the case of food products.

These and other objects are accomplished by a machine that includes a surface positioned over a conveyor line that extends through an open-ended rotating drum, the surface having a discharge edge extending diagonally across the conveyor line. Product to be spread is delivered to the bottom of the drum, and elongated rake-like members circumferentially spaced around the interior of the drum raise portions of the product, as the drum rotates, to a desired discharge point above the surface. The drum has a cylindrical cover of wire mesh or other pervious material that will allow jets of air, from a row of nozzles in a header pipe positioned outside the drum adjacent to the discharge point, to pass through the cover and to blow the portions of product off the tines of each rake member onto the surface.

The shape of the surface in plan view is that of a rectangular trapezoid having one diagonal side that joins the end of a short transverse side at one end of the sur face above the edge of the conveyor nearest to the discharge point from the rakes and that joins the end of a long transverse side at the other end of the surface above the far edge of the conveyor.

The surface may comprise a shaker tray mounted for oscillatory movement in a direction transverse to the drum axis, preferably by means of parallel flexural support legs, the tray being oscillated in that direction, preferably by two pneumatic piston actuators. Alternatively, the surface may comprise a stationary pervious pan fed with air from a plenum below the pan, the shape of the plenum and the perforations of the pan being designed to provide an air cushion of uniform velocity flowing laterally across the surface of the pan toward the diagonal discharge edge.

Product discharges from each rake member near the longitudinal side of the tray or pan opposite the diagonal side and moves under the influence of the oscillations of the tray or the flowing air cushion of the pan laterally across the surface until it drops over the edge of the diagonal side, starting at the near end and moving progressively to the far end as the product uniformly crosses the surface; so that at steady operating conditions an even curtain of product flows over the diagonal edge of the surface to uniformly cover items moving along the conveyor line below.

In order to move the product substantially unidirectionally across the surface of the shaker tray embodi ment, it is desirable that the oscillatory motion have an upward component in the advance half of the cycle and a downward component in the return half, thereby increasing frictional resistance between the product and tray surface during advance and decreasing the resistance during return. This is accomplished by supporting the tray with elongated parallel flexural members that extend at a slant with respect to the vertical direction. Two pneumatic piston actuators drive the tray in this embodiment through connections at each end of a longitudinal bar fastened to the underside of the tray. To prevent unequal or unsynchronized actuating forces from racking the tray, a stabilizing torque tube extending between the actuators is attached through pinconnected links at either end of the tube to the longitudinal bar near each actuator connection.

The tray surface is preferably made of wire screening to reduce the area of contact with the product and resulting sticking and balling, particularly with materials such as mozzarella cheese. Even with a screen surface, however, it has been found in handling grated cheese that particles will stick in the mesh and clog up the screen after only a few hours of operation. This requires shutting down the line, scraping the cheese off the tray, and blowing or brushing the clogging particles out of the screen mesh.

For handling such sticky materials, therefore, it is preferable to use the alternate air pan embodiment of the invention. The air pan comprises a pervious surface, preferably formed of overlapping closely spaced louvers set at a shallow angle with respect to the horizontal in rows parallel to the conveyor line, with the louvers sloping downward away from the diagonal edge of the pan. A blower provides air under low pressure to a plenum beneath the louvered pan, the plenum being designed to supply air flow at uniform velocity through the spaces between adjacent louvers so as to provide a cushion of air moving uniformly across the surface of the pan toward the diagonal discharge edge.

Although the optimum louver size, louver angle, slot spacing, and air velocity through the slots depend on the product being handled, an arrangement comprising one inch wide louvers of 0.048 inch sheet metal set at approximately 8 with a onefourth inch overlap and approximately 0.030 inch spacing provides vey satisfactory results when handling grated mozzarella cheese if sufficient air is supplied to produce uniform flow velocity through the slots of approximately 5000 feet per minute.

The conveyor line for transporting items through the drum preferably terminates just short of the exit end of the drum, with the items being transferred to a second conveyor across a short gap, so that excess product that has fallen on the conveyor endless transport element willbe carried down through the gap to fall to the bottom of the drum. An air header pipe equipped with a row of nozzles may be positioned transversely adjacent to the gap to dislodge product particles that tend to adhere to the conveyor element. For especially sticky products, a doctor blade may be positioned under the forward end of the transport conveyor, preferably outside the drum, to scrape off any product remaining on the surface of the endless conveyor element.

The product spreading apparatus described above is particularly suitable for spreading topping materials on food items because of its simple construction that permits easy and thorough cleaning. Additional features and advantages of the invention will become apparent from the following description of the preferred embodiment as disclosed in the accompanying drawings.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the preferred embodiment of the rotary-drum product spreading apparatus of the invention.

FIG. 2 is a perspective view of a portion of the conveyor transport element inside the drum after passing under the diagonal discharge edge of the product distributing surface of the invention, showing a layer of product spread uniformly over the exposed surfaces of the conveyor element and of a flat item, such as a pizza pie, being transported by the conveyor.

FIG. 3 is a section view of the rotary-drum apparatus taken along the lines 3-3 in FIG. 1 and showing an alternate form of conveyor transport element.

FIG. 4 is a partial section view taken along the lines 44 of FIG. 3.

FIG. 5 is a phantom perspective view of the preferred embodiment of FIG. 1 showing the operative relation between the rotary-drum, shaker tray, and conveyor line of the invention.

FIG. 6 is a top perspective view of the alternate air pan embodiment of the product distributing means of the invention.

FIG. 7 is a top viewof the air pan of FIG. 6.

FIG. 8 is a partial end view in section of the air pan of FIG. 6.

FIG. 9 is a magnified view of a portion of the louvered pan surface of FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, FIG. 1 shows a perspective view looking at the exit end of the preferred embodiment of a product spreading machine according to the present invention. An endless conveyor element, such as flat belt 10 carries a continuous line of items, such as pizza pies l l, in a linear path past a product distrib uting means such as shaker tray 12 positioned above the conveyor line and having a product distribution side.l3 extending diagonally across the path of conveyor element 10.

A means for delivering topping materials, such as grated cheese, mushrooms, sliced sausage, and the like, to the shaker tray for spreading on the pizza pies includes an open-ended rotary drum l4 constructed of two spaced annular end plates 15, 16 and a cylindrical permeable shell 17 of wire mesh or perforated sheet metal wrapped around end plates 15, I6 and secured with latches 18.

Drum 14 is supported for rotation about its axis within a rectangular frame 19 on a pair of curved track segments 20 (only one segment shown), one track segment being attached to each end of the frame by bolts 21. Each track segment supports a circular line of roller pins 22 attached to one of two support rings 23, one of which is welded to each of the annular end plates 15, 16. This above-axis support arrangement avoids contamination by excess topping product that may drop down from the conveyor, but alternate drum support means as shown in my prior reference patents may be substituted, if desired.

The open ends of the drum are partially enclosed by stationary end plates 24, 25 that are attached to frame 19 by bolts 26. The stationary end plates, which help to retain the topping product within the drum, are sized to have a small clearance gap between them and corresponding dmm end plates l5, l6, and they are provided with inlet and exit openings for the line of items to be covered and with access openings for cleaning the shaker tray. In addition, a supply chute 27 is attached to stationary plate 25 for delivery of topping product to the interior of the drum.

Sheet metal sides 28, 29 enclose the lower portion of frame 19 and, together with a sliding troy 30, serve to capture any excess product that may fall outside the drum. A conventional motor drive unit 31 is geared to the conveyor line for advancing endless belt 20 through the drum, and another motor drive unit 32 is coupled through a pinion gear 33 (see FIG. 3) to roller pins 22 for rotating drum 14 in the direction shown by the arrows. A motor controller unit 34 permits an operator stationed at the exit end of the apparatus to control both drive units 31, 32 by means of pushbutton switches 35.

Referring to FIGS. 3-5 for details of the interior arrangement of the product spreading apparatus reveals a number of elongated rake members 36 mounted in circumferentially spaced relation around the periphery of the drum. Each rake member is removably fastened at each end to correspondingly radially slotted mounting lugs 37 attached to each edge of drum shell 17 and is equipped with a plurality of tines 38 that extend through shell 17 at a preset angle to form shelf-like elements around the inside of the drum for carrying por tions of topping product from the bottom of the drum to a predetermined discharge point above the shaker tray. The radial slots in lugs 37 permit adjustment of the rakes inwardly or outwardly of the drum to lengthen or shorten, respectively, the effective length of the tines 38 protruding through the drum cover and thereby selectively vary the amount of product picked up by each rake member as the drum rotates.

An air supply header pipe 39 equipped with a row of nozzles 40 is mounted just outside the path of rake members 36 at the discharge point (approximately the 10 oclock position in FIG. 3) for directing blasts of air at the tines of each rake in turn to blow the portions of product off the rakes to fall onto the shaker tray. To conserve air, the supply to header 39 is preferably controlled by a valve actuated by means (not shown) synchronized with the drum rotation to open only when a rake member is passing the discharge station. Such actuating means could be, for example, a lever positioned in the path of the rake members and coupled to the valve controlling means.

Shaker tray 12 comprises a frame fabricated of flat stock in the shape of a rectangular trapezoid having a longitudinal side member 41, a short transverse side member 42, a long transverse side member 43, and a diagonal side member 44. Spaced support members 45 extend between the longitudinal and diagonal sides parallel to the transverse sides for adding rigidity to the tray frame and for supporting the tray surface, which is preferably made of wire screening 46 to reduce surface tension and adhesion of the product to the tray.

Tray side members 41, 42, and 43 extend above the surface of screen 46 to provide barriers against loss of the product from the back and ends of the tray.

Tray 12 is supported over the conveyor line by two rear flexure members 47 and two front flexure members 48, preferably made of laminated nylon. Rear flexure members 47 are attached at their lower ends to a longitudinal rod 49 fastened to stationary end plates 24, 25 by machine screws 50 and at their upper ends to a longitudinal bar 51 attached to the underside of the shaker tray adjacent to longitudinal side member 41. Front flexure members 28 are attached at their lower ends to a pair of studs 52 that also are fastened to stationary end plates 24, 25 by machine screws 53 and at their upper ends to a longitudinal bar 54 that is rigidly attached to shaker tray 12 through upright lugs 55 formed integrally from transverse side members 42, 43.

A pair of pneumatic piston actuators 56 are attached to rod 49, at either end adjacent to rear flexure members 47, and to a longitudinal bar 57 mounted to the underside of the tray parallel to bar 51. Between the actuators is a torque tube 58 concentrically mounted on rod 49 and connected at either end to longitudinal bar 57 through a pair of lever arms 59 welded to the torque tube and hinge links 60 connected to the outer end of the lever arms by pins 61 and to longitudinal bar 57 by clamp blocks 62.

In operation, high pressure air is supplied alternately through flexible hoses 63, 64 by automatically cycling control valve means (not shown) to drive each pneumatic actuator 56 in oscillatory motion at a preselected controllable frequency. The oscillatory forces exerted by the actuators between stationary support rod 49 and bar 57 causes the tray to oscillate back and forth on flexural members 47, 48 as indicated by the arrows.

Because the flexural members are slanted, the tray has an upward component of motion on each advance stroke and a downward component on each return stroke, as shown by the double-ended arrows in FIG. 3. Thus the product deposited on the tray tends to move forward (to the right) with the tray on the advance stroke and to remain stationary as the tray moves back ward (to the left) on the return stroke. The net result is that the product moves progressively to the right with respect to the surface of the tray until it cascades over the diagonal edge 13.

If the actuator operation is perfectly synchronized, hinge links 60 transmit no differential force to lever arms 50, but if the actuator forces are unbalanced (due to unequal hose lengths from the control valve or different flow resistance in the lines, for example), they tend to rack the tray, thereby placing excessive loads on the flexure members. These racking forces are transmitted through the hinge links and lever arms, however, and establish a torque in tube 58 that resists the unbalanced actuating forces, thus relieving the strain on the flexure members.

The complete operation of the apparatus is shown most clearly in FIG. 5. Food items such as pizza pies 11 are delivered from a previous work station on a feed conveyor 65, from which they transfer to conveyor transport element 10. This support element is shown in FIGS. 1, 2 and 5 as an endless flat belt extending between smooth rollers 66, 67, but it may be alternatively a plurality of parallel endless cords a (FIG. 3) stretched over grooved roller 66a and an exit roller (not shown). The parallel cords provide the advantage of allowing excess product from the shaker to pass directly through to the bottom of the drum for recycling.

With the flat belt conveyor, excess product is distributed in a layer on the exposed belt surface, as shown in FIG. 2. To prevent carryout of this excess product, conveyor l0 terminates short of the drum exit, and the pizza pies are transferred to an inclined doughnut wheel conveyor 68 that allows any loose product near the edges of the pies to drop through the gap between conveyors l0 and 68 into the bottom of the drum or between the doughnut wheels onto sliding tray (FIG. 1).

As the flat belt rounds the exit roller, jets of air from a row of nozzles 69 in an air supply header 70 tend to dislodge any product that does not fall from the belt surface under the influence of gravity. Any particles that still adhere to the belt surface will be removed by a doctor blade 71 mounted underneath conveyor 10 near the entrance roller 66.

Referring to FIGS. 6 9, an alternate product distributing means in the form of a stationary louvered air pan 73 may be substituted for the shaker tray 12 and is preferred when handling sticky and gummy products such as mozzarella cheese.

Air pan 73 comprises a frame fabricated of flat stock in the shape of a rectangular trapezoid identical in shape and size to the shaker tray frame and having a longitudinal side member 41, a short transverse side member 42, a long transverse side member 43, and a diagonal side member 44. Spaced support members 45 extend between the longitudinal and diagonal side members parallel to the transverse side members for adding rigidity to the pervious pan surface 74.

Pan surface 74 preferably is formed of a plurality of louvers 75 welded or otherwise attached to sawtooth steps notched in the upper edges of support members 45'. Each louver extends substantially parallel to longitudinal side member 41, is set at a shallow angle with respect to the horizontal, and overlaps and is spaced from each adjacent louver to provide a corresponding plurality of sapced slots parallel to longitudinal side member 41 and facing in the direction of the diagonal edge 76 formed by the intersection of pan surface 74 and diagonal side member 44'.

A flow of air is supplied from a blower (not shown) through a duct 77 connected to one end of a tapered header 78 extending underneath the rear of the pan, thence transversely of a longitudinally tapered passageway formed between a substantially conical inner surface 79 and a substantially cylindrical outer surface 80 attached to the reaper wall of tapered header 78 to discharge into the rear portion of a plenum chamber underneath the louvered pan surface. The bottom of the plenum chamber lies in a plane 81 that intersects to pan surface 74 along diagonal edge 76 and that slants downwardly and rearwardly to form a acute angle with the plane of the pan surface.

The angles of taper of header 78, conical surface 80, and bottom plane 81 are chosen to produce substantially uniform pressure at all points in the plenum chamber and, consequently, substantially uniform flow velocity through the slots of the louvered pan. Because of the shallow angle of the louvers, the air flowing through the slots between louvers at uniform velocity will form a cushion of air moving laterally across the pan surface toward diagonal edge 76. This air cushion will literally float the particles of grated cheese or the like uniformly across the pan surface with no problems of sticking or clogging.

As mentioned earlier, satisfactory results have been obtained when handling shredded mozzarella cheese with an air pan of the following specifications:

Louver width 1 inch Louver thickness .048 inch Louver angle 8 /2 degrees Louver overlap A inch Louver spacing .03 inch Air velocity 5000 ft/min The necessary size of blower required can be calculated easily by multiplying the louver spacing by the lineal total slot dimension to obtain total flow across section which, when multiplied by the desired slot air velocity, will yield the required flow capacity of the blower.

It will be appreciated that the foregoing dimensions and velocities are intended to be exemplary only, and those skilled in the art may determine other dimensions and arrangements within the scope of the invention.

ln addition, while the preferred embodiments of the invention have been shown and described, changes, additions, and substitutions of equivalent components can be made without departing from the spirit and scope of the invention.

What is claimed is:

1 A machine for spreading a uniform layer of particulate materials on the top surfaces of fiat items comprising:

a conveyor for transporting the food items along a linear path;

a material distribution member having a surface bounded on one side by an edge extending over the conveyor in a direction diagonal to the linear path for a lateral distance at least equal to the maximum width of items on the conveyor;

means for delivering portions of the materials to be spread on the food items to a region of the surface of the distribution member spaced laterally from the diagonal edge, the portions of materials being delivered by said means substantially uniformly along a line parallel to the linear path; and

means for advancing the delivered materials substantially uniformly across the surface of the distribution member in a direction transverse to the linear path and toward the diagonal edge to cascade over said edge in a uniform curtain of flow spanning at least the maximum width of the items to be covered.

2. The machine of claim 1 wherein the material distribution member comprises a shaker tray, and the means for advancing the material across the surface of the distribution member comprises:

means for supporting the shaker tray for oscillatory motion in a direction transverse to the linear path; and

means for driving the shaker tray in said oscillatory motion for advancing the materials across the shaker tray to cascade over the diagonal edge in a uniform curtain of flow spanning at least the maximum width of the items to be covered.

3. The machine of claim 2 wherein the means for supporting the shaker tray for oscillatory motion in a direction transverse to the linear path comprises:

means for imparting an upward component of motion to the tray during the portion of each oscillatory cycle that the tray is advancing toward the linear path and for imparting a downward component of motion to the tray during the portion of each oscillatory cycle that the tray is retreating from the lin ear path.

4. The machine of claim 2 wherein the means for supporting the shaker tray for oscillatory motion in a direction transverse to the linear path comprises:

a plurality of elongated support members, each support member being connected to the tray at one end and to a fixed point at the other end for hingetype movement about the ,fixed point in a plane transverse to the linear path, the attitude of each support member with respect to the vertical direction being such that the end attached to the tray will undergo an upward component of movement during the advance portion of each cycle of tray motion and a downward component of movement during the return portion of each oscillatory cycle.

5. The machine of claim 4 wherein the plurality of support members are parallel to each other and are slanted with respect to the vertical direction during all phases of the oscillatory tray motion.

6. The machine of claim 5 wherein the plurality of support members comprise:

a first pair of members having their tray-connected ends above their fixed point-connected ends and a second pair of members having their trayconnected ends below their fixed point-connected ends.

7. The machine of claim 2 further comprising torsional stabilizing means connected to the tray for counteracting unbalanced oscillatory forces tending to rack the tray, said stabilizing means including:

an elongated torsional member mounted concentrically with a fixed axis that is perpendicular to the direction of oscillatory tray motion;

first and second lever arms rigidly attached to each end of the torsional member and extending approx imately vertically; and

first and second link members extending approximately horizontally in a direction transverse to the linear path, each link member having one end pivotally connected to the outer end of the respective lever arm and having the other end pivotally con nected to the tray, wherey forces tending to rack the tray about a substantially vertical axis are opposed by torsional reaction forces developed in the torsional member and transmitted through the lever arms and link members to the tray.

8. The machine of claim 1 wherein the material distribution member comprises:

an air pan including a hollow plenum with a pervious upper surface having a multiplicity of spaced substantially uniformly distributed apertures leading from inlets in the plenum to outlets on the upper surface. the apertures being oriented so that air flowing from the plenum through the apertures will leave the outlets in a direction transverse to the linear path and toward the diagonal edge of the air pan, and

the means for advancing the delivered materials substantially uniformly across the surface of the distribution member in the direction of the diagonal edge comprises:

means for supplying a flow of air to the plenum for distribution through the apertures of the pervious upper surface at substantially uniform velocities sufficient to form a moving cushion of air for carrying the particulate materials transversely across the surface to cascade uniformly over the diagonal edge.

9. The machine of claim 8 wherein the pervious upper surface of the air pan comprises:

a plurality of spaced louvers extending substantially parallel to the linear path, each louver being set at a shallow angle with respect to the plane of the upper surface and overlapping each adjacent louver, and the spaces between adjacent louvers forming the appertures for the air flowing from the plenum 10. The machine of claim 8 wherein the means for supplying a flow of air into the plenum comprises:

a duct having an outlet into the plenum, and

a blower mounted in the duct for blowing air through the duct into the plenum, and

the depth of the plenum decreases as a function of distance from the outlet of the duct in order to maintain the pressure throughout the plenum substantially uniform, whereby the velocity of flow through the apertures also will be substantially uniform.

1 1. In a machine for distributing particulate materials of the type that includes means for conveying items along a linear path, an open-ended drum surrounding at least a portion of the conveying means with the drum axis extending substantially in the direction of the linear path, means for supporting the drum for rotation about its axis, means for rotating the drum on the support means, means for delivering to the interior of the drum materials to be distributed to the items on the conveyor, means spaced around the periphery of the drum for raising portions of the materials in the drum as the drum rotates and for releasing the materials at a preselected discharge line above the level of the con veying means, and means for directing materials dis charged from the raising means to the items as they are conveyed along the linear path, the improvement wherein the means for directing materials discharged from the raising means to the items as they are conveyed along the linear path comprises:

a trapezoidal surface positioned inside the drum below the preselected discharge point and above the conveying means, the surface having a longitudinal side extending substantially parallel to the linear path of the conveying means laterally outboard of the preselected discharge line and an edge opposite the longitudinal side and extending diagonally with respect to the linear path over the items on the conveying means, and

means for advancing the materials discharged from the raising means substantially uniformly across the surface in a direction transverse to the longi tudinal side and toward the diagonal edge of cas cade over said edge in a uniform curtain of flow spanning at least the maximum width of the items to be covered.

12. The machine of claim 1 1 wherein the trapezoidal surface comprises a shaker tray, and the means for advancing the materials substantially uniformly across the surface comprises:

means for supporting the tray for oscillatory motion in a direction transverse to the drum axis; and means for shaking the tray ,in said oscillatory mo tion for advancing the materials discharged from the raising means across the surface of the tray to cascade over the discharge edge in a uniform curtain of flow that spans the width of the items on the conveying means.

13. The machine of claim 11 wherein the trapezoidal surface comprises:

an air pan including a hollow plenum with a pervious upper surface having a multiplicity of spaced substantially uniformly distributed apertures leading from inlets in the plenum to outlets on the upper surface, the apertures being oriented so that air flowing from the plenum through the apertures will leave the outlets in a direction transverse to the longitudinal side and toward the diagonal edge of the surface, and the means for advancing the materials substantially uniformly across the surface comprises: means for supplying a flow of air to the plenum for distribution through the apertures of the pervious upper surface at substantially uniform velocities sufficient to form a moving cushion of air for carrying the particulate materials transversely across the surface to cascade uniformly over the diagonal edge.

14. The machine of claim 11 wherein the means spaced around the periphery of the drum for raising portions of the materials in the drum as the drum rotates and for releasing the materials at a preselected discharge line above the level of the conveyor means comprises:

elongated rake members, each rake member including a support rod adapted to be removably fastened to the exterior of the drum parallel to the drum axis and a plurality of tines extending perpendicularly from the support rod into the drum at a preselected angle to the inner surface of the drum, the spacing between adjacent tines being suitable for retaining portions of the particulate materials in the bottom of the drum as the drum rotates for raising the portions to the preselected discharge point;

means for removably fastening the support rod of each rake member to the exterior of the drum; and

means for blowing the portions of materials off the tines of each rake member onto the tray at the preselected discharge line 15. The machine of claim 14 wherein the means for removably fastening the support rod of each rake memher to the exterior of the drum comprises:

a pair of mounting plates fixed to the exterior of the drum and longitudinally spaced by the length of the support rod, each mounting plate having a slot ex tending radially with respect the drum axis, and

threaded means for removably fastening each end of the support rod to a respective mounting plate so as to permit radial adjustment of the support rod end over the length of the radial slot, whereby the effective length of the rake tines extending from the inner surface of the drum can be adjusted to vary the amount of material picked up as the drum rotates.

16. The machine of claim 11 wherein the means for conveying items along a linear path comprises:

a first horizontal roller supported in front of the entrance end of the drum for rotation about an axis perpendicular to the linear path;

a second horizontal roller supported inside the drum adjacent to the exit end for rotation about an axis perpendicular to the linear path;

an endless belt trained around the first and second rollers for moving along the linear path upon rota tion of the rollers;

means for driving the first roller in a direction for means positioned inside the drum adjacent to and below the second roller'for blowing loosely adherent materials from the surface of the endless belt as it passes around the second roller, said materials then falling to the bottom of the drum, and

a doctor blade positioned outside the drum adjacent to and below the first roller for scraping strongly adherent materials not removed by the blowing means from the surface of the belt, said materials then falling outside the drum so as not to mix with the materials in the bottom of the drum.

UNITED STATES PATENT OFFICE Patent No.

Inventor (s) Dated September 16, 1975 Bernard Eisenberg It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, line Column 7, line Column 7, line Column 8, line Column 9, line Column 54, vchange "wherey" to -whereby--.

10, line 21, change "appertures" to apertures.

Column 10, line 67, change "edge of" to -edge to--.

[SEAL] Sign! and Scaled this second Day of December1975 AIICSI.

RUTH C. MASON Arresting Officer 

1. A machine for spreading a uniform layer of particulate materials on the top surfaces of flat items comprising: a conveyor for transporting the food items along a linear path; a material distribution member having a surface bounded on one side by an edge extending over the conveyor in a direction diagonal to the linear path for a lateral distance at least equal to the maximum width of items on the conveyor; means for delivering portions of the materials to be spread on the food items to a region of the surface of the distribution member spaced laterally from the diagonal edge, the portions of materials being delivered by said means Substantially uniformly along a line parallel to the linear path; and means for advancing the delivered materials substantially uniformly across the surface of the distribution member in a direction transverse to the linear path and toward the diagonal edge to cascade over said edge in a uniform curtain of flow spanning at least the maximum width of the items to be covered.
 2. The machine of claim 1 wherein the material distribution member comprises a shaker tray, and the means for advancing the material across the surface of the distribution member comprises: means for supporting the shaker tray for oscillatory motion in a direction transverse to the linear path; and means for driving the shaker tray in said oscillatory motion for advancing the materials across the shaker tray to cascade over the diagonal edge in a uniform curtain of flow spanning at least the maximum width of the items to be covered.
 3. The machine of claim 2 wherein the means for supporting the shaker tray for oscillatory motion in a direction transverse to the linear path comprises: means for imparting an upward component of motion to the tray during the portion of each oscillatory cycle that the tray is advancing toward the linear path and for imparting a downward component of motion to the tray during the portion of each oscillatory cycle that the tray is retreating from the linear path.
 4. The machine of claim 2 wherein the means for supporting the shaker tray for oscillatory motion in a direction transverse to the linear path comprises: a plurality of elongated support members, each support member being connected to the tray at one end and to a fixed point at the other end for hinge-type movement about the fixed point in a plane transverse to the linear path, the attitude of each support member with respect to the vertical direction being such that the end attached to the tray will undergo an upward component of movement during the advance portion of each cycle of tray motion and a downward component of movement during the return portion of each oscillatory cycle.
 5. The machine of claim 4 wherein the plurality of support members are parallel to each other and are slanted with respect to the vertical direction during all phases of the oscillatory tray motion.
 6. The machine of claim 5 wherein the plurality of support members comprise: a first pair of members having their tray-connected ends above their fixed point-connected ends and a second pair of members having their tray-connected ends below their fixed point-connected ends.
 7. The machine of claim 2 further comprising torsional stabilizing means connected to the tray for counteracting unbalanced oscillatory forces tending to rack the tray, said stabilizing means including: an elongated torsional member mounted concentrically with a fixed axis that is perpendicular to the direction of oscillatory tray motion; first and second lever arms rigidly attached to each end of the torsional member and extending approximately vertically; and first and second link members extending approximately horizontally in a direction transverse to the linear path, each link member having one end pivotally connected to the outer end of the respective lever arm and having the other end pivotally connected to the tray, wherey forces tending to rack the tray about a substantially vertical axis are opposed by torsional reaction forces developed in the torsional member and transmitted through the lever arms and link members to the tray.
 8. The machine of claim 1 wherein the material distribution member comprises: an air pan including a hollow plenum with a pervious upper surface having a multiplicity of spaced substantially uniformly distributed apertures leading from inlets in the plenum to outlets on the upper surface, the apertures being oriented so that air flowing from the plenum through the apertures will leave the outlets in a direction transverse to the linear path and toward the diagonal edge of the air pan, and the means for advancing the delivered materials substantially uniformly across the surface of the distribution member in the direction of the diagonal edge comprises: means for supplying a flow of air to the plenum for distribution through the apertures of the pervious upper surface at substantially uniform velocities sufficient to form a moving cushion of air for carrying the particulate materials transversely across the surface to cascade uniformly over the diagonal edge.
 9. The machine of claim 8 wherein the pervious upper surface of the air pan comprises: a plurality of spaced louvers extending substantially parallel to the linear path, each louver being set at a shallow angle with respect to the plane of the upper surface and overlapping each adjacent louver, and the spaces between adjacent louvers forming the appertures for the air flowing from the plenum
 10. The machine of claim 8 wherein the means for supplying a flow of air into the plenum comprises: a duct having an outlet into the plenum, and a blower mounted in the duct for blowing air through the duct into the plenum, and the depth of the plenum decreases as a function of distance from the outlet of the duct in order to maintain the pressure throughout the plenum substantially uniform, whereby the velocity of flow through the apertures also will be substantially uniform.
 11. In a machine for distributing particulate materials of the type that includes means for conveying items along a linear path, an open-ended drum surrounding at least a portion of the conveying means with the drum axis extending substantially in the direction of the linear path, means for supporting the drum for rotation about its axis, means for rotating the drum on the support means, means for delivering to the interior of the drum materials to be distributed to the items on the conveyor, means spaced around the periphery of the drum for raising portions of the materials in the drum as the drum rotates and for releasing the materials at a preselected discharge line above the level of the conveying means, and means for directing materials discharged from the raising means to the items as they are conveyed along the linear path, the improvement wherein the means for directing materials discharged from the raising means to the items as they are conveyed along the linear path comprises: a trapezoidal surface positioned inside the drum below the preselected discharge point and above the conveying means, the surface having a longitudinal side extending substantially parallel to the linear path of the conveying means laterally outboard of the preselected discharge line and an edge opposite the longitudinal side and extending diagonally with respect to the linear path over the items on the conveying means, and means for advancing the materials discharged from the raising means substantially uniformly across the surface in a direction transverse to the longitudinal side and toward the diagonal edge of cascade over said edge in a uniform curtain of flow spanning at least the maximum width of the items to be covered.
 12. The machine of claim 11 wherein the trapezoidal surface comprises a shaker tray, and the means for advancing the materials substantially uniformly across the surface comprises: means for supporting the tray for oscillatory motion in a direction transverse to the drum axis; and means for shaking the tray in said oscillatory motion for advancing the materials discharged from the raising means across the surface of the tray to cascade over the discharge edge in a uniform curtain of flow that spans the width of the items on the conveying means.
 13. The machine of claim 11 wherein the trapezoidal surface comprises: an air pan including a hollow plenum with a pervious upper surface having a multiplicity of spaced substantially uniformly distributed apertures leading from inlets in the plenum to outlets on the upper surface, the apertures being oriented so that air flowing from the plenum through the apertures will leave the outlets in a direction transverse to the longitudinal side and toward the diagonal edge of the surface, and the means for advancing the materials substantially uniformly across the surface comprises: means for supplying a flow of air to the plenum for distribution through the apertures of the pervious upper surface at substantially uniform velocities sufficient to form a moving cushion of air for carrying the particulate materials transversely across the surface to cascade uniformly over the diagonal edge.
 14. The machine of claim 11 wherein the means spaced around the periphery of the drum for raising portions of the materials in the drum as the drum rotates and for releasing the materials at a preselected discharge line above the level of the conveyor means comprises: elongated rake members, each rake member including a support rod adapted to be removably fastened to the exterior of the drum parallel to the drum axis and a plurality of tines extending perpendicularly from the support rod into the drum at a preselected angle to the inner surface of the drum, the spacing between adjacent tines being suitable for retaining portions of the particulate materials in the bottom of the drum as the drum rotates for raising the portions to the preselected discharge point; means for removably fastening the support rod of each rake member to the exterior of the drum; and means for blowing the portions of materials off the tines of each rake member onto the tray at the preselected discharge line.
 15. The machine of claim 14 wherein the means for removably fastening the support rod of each rake member to the exterior of the drum comprises: a pair of mounting plates fixed to the exterior of the drum and longitudinally spaced by the length of the support rod, each mounting plate having a slot extending radially with respect the drum axis, and threaded means for removably fastening each end of the support rod to a respective mounting plate so as to permit radial adjustment of the support rod end over the length of the radial slot, whereby the effective length of the rake tines extending from the inner surface of the drum can be adjusted to vary the amount of material picked up as the drum rotates.
 16. The machine of claim 11 wherein the means for conveying items along a linear path comprises: a first horizontal roller supported in front of the entrance end of the drum for rotation about an axis perpendicular to the linear path; a second horizontal roller supported inside the drum adjacent to the exit end for rotation about an axis perpendicular to the linear path; an endless belt trained around the first and second rollers for moving along the linear path upon rotation of the rollers; means for driving the first roller in a direction for causing the upper surface of the endless belt to move toward the exit end of the drum and around the second roller for return to the entrance end, whereby excess materials deposited on the belt from the oscillating tray will tend to fall from the belt as it passes around the second roller and drop to the bottom of the drum for recycling by the raising means.
 17. The machine of claim 16 further comprising: means positioned inside the drum adjacent to and below the second roller for blowing loosely adherent materials from the surface of the endless belt as it passes around the second roller, said materials then falling to the bottom of the drum, and a doctor blade positioned outside the drum adjacent to and below the first roller for scraping strongly adherent materials not removed by the blowing means from the surface of the belt, said materials then falling outside the drum so as not to mix with the materials in the bottom of the drum. 